Cisco etherchannel computer skills flashcards quizlet. The truth is that stp does a lot more than just help avoid network loops which in turn causes network broadcast storms. You would use it if you wanted to protect your spanning tree root, regardless of weather you are using lacp or not. On by default sh etherchannel sh etherchannel 1 detail. Hence the etherchannel misconfig guard feature just detects if it is receiving its opposite switch bpdus on other ports of the etherchannel. To disable the etherchannel guard feature, use the no spanningtree etherchannel guard misconfig global configuration command. How to enable spanning tree portfast in cisco catalyst switch ios stp portfast is a feature in cisco ios which allows a switchport which is participating in stp to directly transition from blocking mode to forwarding mode when a device connects and the link goes up. To return to the default settings, use the no form of this command. Core sw1config# spanningtree etherchannel guard misconfig. Enable fastethernet00 which is connected to fa01 then observe the switches spanning tree behavior via the show spanning tree command.
Spanning tree shuts down ports that are in a port fastoperational. Catalyst 3750x and 3560x switch software configuration guide, release 12. Oct 28, 2011 well, you configure rootguard at the interface level with the spanningtree guard root command. Nov 15, 2011 spanning tree portfast end but when i had to force the server to shutdown recently it created a loop and interrupted traffic on the 150 vlan. Run the bridge command to edit the bridge, and then the spanning tree command to change the settings. This is because should there be a mismatch, it will be removed from the bundle and set to independent mode, at which point spanning tree will kick in and make all well until the configuration can be corrected. Jun 21, 2010 but spanning tree etherchannel guard misconfig keeps showing up. Ethernet devices running the spanning tree protocol stp have been. If you omit this parameter, the system uses the port number you specified when you issued the interface command to enter the interface configuration mode. I had an instance where 2 ports on a switch were configured with via trunk ports properly however the opposing switch was only had one port switch as a trunk, the 2nd as a regular access port. Sep 11, 2018 to disable the etherchannel guard feature, use the no spanning tree etherchannel guard misconfig global configuration command.
Run the bridge command to edit the bridge, and then the spanningtree command to change the settings. Many cisco switches are still connected on the hp some in daisychaining. This could be that there are some parameters not matching up such as duplex and speed. You can use static etherchannels, with no associated protocol, for a simplified configuration. If a port enabled with bpdu guard receives a bpdu, it is. A channel is supposed to be point to point and the feature is adding a consistency check based on the source mac address of the bpdu received. This is because should there be a mismatch, it will be removed from the bundle and set to independent mode, at which point spanningtree will kick in and make all well until the configuration can be corrected. Spanning tree protocol in layer 2layer 3 environments rather than rely on chance, it is important to configure the bridge priority on the switch to make sure that it becomes the root switch. Why etherchannel misconfig guard is a disaster in mixed. This command prevents the interface from sending or receiving bpdus. Disabling spanning tree algorithm on windows bridge. If you put in no spanning tree etherchannel guard misconfig, it does.
Enables uplinkfast to accelerate the choice of a new root port when a link or switch fails or when the spanning tree reconfigures itself. Spanning tree blocking dhcp requests in windowsbootp. A switch has been configured with the vlan dot1q tag native command. Stp etherchannel bpdu misconfig guard, layer 3 etherchannel. Is executed in global configuration mode to configure the switch to use the 802. Hi, im looking for many days some informations about the compatibilty over spanningtree etherchannel guard misconfig and the new i. How to use a msconfig to troubleshoot a configuration issue. Jan 28, 2015 or doesnt ever work, depending on who you ask including me it is on by default, so you dont have to actually configure it which you would do with the global spanningtree etherchannel guard misconfig command, but its definitely not something you want to count on in lieu of actually paying attention to how you are configuring. Similar functionality is built into rapid spanning tree.
Spanning tree shuts down ports that are in a port fastoperational state if any. Lets say the 3750 is the root of the spanning tree. R1 con0 is now available press return to get started. Is there something i am missing in the config that i need to fix so spanning tree will allow traffic through.
Once youve used the switchport host command your can then run whatever additional commands are needed such as spanning tree bpduguard enable or spanning tree bpduguard enable. You can use the show interfaces status errdisabled privileged exec command to show which switch ports are disabled because of an etherchannel misconfiguration. In an etherchannel, the spanning tree bpdus are sent only on the first link of that etherchannel. How to enable spanning tree portfast in cisco catalyst. When configured in this manner, a switch in a stack could fail taking two links with it, but the second switch in the stack would continue to operate. Spanning tree with etherchannel solutions experts exchange.
To see a summary of the spanning tree protocol settings, run the interface command, and then the show stp command. Learning bridges that run the spanning tree protocol are called transparent bridges. Vlan0001, vlan0160, vlan0182, vlan0199, vlan0438, vlan0585 vlan0756, vlan0783, vlan0870, vlan0888vlan0889, vlan0990 etherchannel misconfig guard is enabled extended system id is enabled portfast default is disabled portfast edge bpdu guard default is disabled. Lacp will pick up misconfigured speed and duplex settings between ports, and that is about it. Home intime networking advanced networking concepts disabling spanning tree algorithm on windows bridge. Feb 15, 2016 etherchannel guard is a way of finding out if one end of the etherchannel is not configured properly.
Depending on configuration, this could lead to a network meltdown as the network is busy recalculating spanning tree changes in stead of forwarding. Spanning tree protocol in layer 2layer 3 environments. Once youve used the switchport host command your can then run whatever additional commands are needed such as spanningtree bpduguard enable or spanningtree bpduguard enable. On an access port, both spanningtree portfast and spanningtree portfast trunk cause the port to act as a portfastenabled i. Ive removed the spanning tree portfast command assuming that the port would look for loops before going into forwarding mode. If designed properly, stp can be used to perform loadbalancing between network switches. In the show run all, it is toggled as no spanningtree etherchannel guard misconfig by default. Configuring switchport spanning tree portfast free ccna. Implementing and troubleshooting etherchannel hack and tinker. Portfast port vs edge port the it networking community. The root guard feature can be enabled by using the spanningtree guard root command in interface configuration mode. Catalyst 3560 switch software configuration guide, release. For example, if you configure spanning tree protocol stp parameters on the etherchannel, the cisco nxos applies those parameters to each interface in the etherchannel.
Configure spanning tree protocol settings in the cli. When clients start acting as spanning tree endpoints, this means they can also insert bpdu packets into the network thus triggering the root bridge to recalculate. What would be a solution to the risk of having a single etherchannel switch taking down the entire etherchannel. Stp etherchannel bpdu misconfig guard, layer 3 etherchannel, and etherchannel loadsharing labbed. Using layer 2 extends spanning tree protocol stp over the etherchannel. On a site, i changed the campus core with an hp 10504. Configuring rapid pervlan spanning tree protocol free. From what i now understand stp is the problem, the switch is blocking the dhcp request while it checks for a loop. All configurations that do not relate to physical aspects of the ports that are member of the etherchannel must be configured on the portchannel interface now.
Is there something i am missing in the config that i need to fix so spanningtree will allow traffic through. This is the reason it is strongly recommended to use a dynamic negotiation protocol to allow the switches to negotiate the port channel and verify if the links are eligible for bundling. Bpdu guard can be enabled on all access ports that have portfast enabled. When there is a misconfiguration found, the switch will place the interfaces in errordisabled. Ether channels are designed to provide the fault tolerant high capacity links between servers, routers and switches. They just decided to reuse that command instead of creating a. Enable fastethernet00 which is connected to fa01 then observe the switches spanningtree behavior via the show spanningtree command. It can disable or reenable software, device drivers and windows services. An engineer has run the show etherchannel summary command and the output is displayed. Implementing and troubleshooting etherchannel hack and. What does the msconfig utitility do in windows 7 on your dell pc. Such a port will immediately become forwarding after coming up.
Span the etherchannel across several switches in a virtual stack configuration. Etherchannel bonding portchannel network redundancy. I cant see spanning tree affecting downloads in anyway at all it is a mechanism to prevent switching loops which in turn prevents broadcast storms and the like. By default, spanningtree etherchannel guard misconfig is enabled by default on the 4900m. Solved windows server bridged nics and spanningtree on. How to configure and verify etherchannels ether channels are designed to provide the fault tolerant high capacity links between servers, routers and switches. This command prevents the interface from sending or receiving. I did the no form of the command but when i shut the switch down to move it, then booted it up in its permanent place in the network, spannning tree etherchannel guard misconfig was back and i had to do the no for of the command again. Hi, im looking for many days some informations about the compatibilty over spanning tree etherchannel guard misconfig and the new i. Configuring rapid pervlan spanning tree protocol free ccna. From what i now understand stp is the problem, the switch is blocking the dhcp request while it checks for a loop and the pc misses its dynamic ip while windows boots. Etherchannels can be used to enhance the bandwidth between data centre and wiring closets, you can also apply it anywhere in network where the bottlenecks can possibly occur. What is the best practice when configuring etherchannel on cisco switches to prevent a stp loopbroadcast storm when etherchannel is misconfigured.
To enable etherchannel guard, issue the global command. This does not affect performance at all, we do see that it is enabled by default and that it toggles correctly when doing spanning tree etherchannel guard misconfig or no spanning tree etherchannel guard misconfig. Essentially, if the switch sees any superior bpdus from a switch advertising a lower bridgeid than the current root bridge on an interface configured for root guard, the switch puts that interface into a special stp state called rootinconsistent. You can use etherchannel guard to detect an etherchannel. On an access port, both spanning tree portfast and spanning tree portfast trunk cause the port to act as a portfastenabled i. The bridge priority defaults to 32768 but is configurable from 0 to 65536. If i disable spanning tree on switch a communication between two switches works. Spanning tree protocol features security features on switches. Getting errdisable when trying to bring up etherchannel. Using this command will automatically lower the priority of the switch to a very significant value in order. In order to verify if the configuration is correct, enter the following to view the ports that have been assigned to the portchannel.
Or it could be that one side is a trunk and the other isnt. Catalyst 3750x and 3560x switch software configuration. The spanning tree protocol for bridges, standardized in the ieee 802. I only discovered point 3 recently, and have disabled stp on the switches to correct the issue for now. Etherchannel guard is a way of finding out if one end of the etherchannel is not configured properly. This is done by organizing the bridges in a spanning tree topology. How to enable spanning tree portfast in cisco catalyst switch. Enable the spanning tree for the specified port or ports. These are issues where new commands have been set or. Using the command spanning tree vlan list root primary secondary. Sep 07, 2016 you can watch the full lab by topic at the links below. Bpdu guard is best deployed on userfacing ports to prevent rogue switch network extensions by an attacker. The way to define an edge port on cisco devices is to use spanningtree portfast.
Mar 10, 2016 stp etherchannel misconfig is active by default and can be deactivated using the no spanning tree etherchannel guard misconfig global config command. To see a summary of the spanning tree settings, run the show bridge command. The switchport host command is a macro on all cisco switches. Stp spanning tree protocol ios network command reference. Msconfig is a system utility to troubleshoot the microsoft windows startup process. Due to the spanning tree algorithm, it may take 10 to 12 seconds for the windows bridge to allow packets to pass through from the intime portion of the bridge. To enable or disable loop guard or root guard, use the spanningtree guard command. These two commands differ if the port is operating as a trunk port either by static configuration or via dtp negotiation.